In the 80's, Salvatore Contini, a member of the Sardinian mafia, and Jean marc Leccia, a famous chemist of the French connection, killed Guy Orsoni, a member of an important criminal clan which is still active today and runs part of Southern Corsica. Contini and Leccia were quickly arrested.
At the time, the Orsoni clan was also involved with the independantist guerilla in Corsica so it had 3 of their guys break in to the prison and kill Contini and Leccia then surrender to the police.
That's the Corsicans for you...Fierce people.
They probably were among the toughest, smartest and most sophisticated criminals of the last century, they were just too few of them so they never could become as big as the Italians, Colombians, Russians etc.